Doctors in New York say former President Bill Clinton is awake and resting comfortably after surgery earlier Thursday to clear up complications from last year's heart surgery.

Doctors at New York Presbyterian Hospital call the operation successful.

Surgeons removed fluid and scar tissue that had built up around Mr. Clinton's left lung since last September's quadruple heart bypass surgery. Doctors say the condition is unusual but non-life threatening.

Doctors say Mr. Clinton's lung is very healthy and they expect it will be fully functional. Mr. Clinton is expected stay in the hospital for three to 10 days.

The former president had recently complained of shortness of breath. He has been extremely active since his September surgery, including taking a trip to tsunami-struck areas of South Asia.